Water Absorption Study Recycled Aggregates for Use Pavement Material

Water absorption properties of recycled materials play an important role in pavement performance. The performance of aggregates changes after absorbing water, then it affects highways layers such as base, subbase, capping. This is why these materials must comply requirements of codes and standards. With regard to the increasing trend of application of recycled aggregates in highways layers, this issue needs more investigation. This research is only a part of our large research programme on three different purposed mixes of unbound subbase mixture below: 1) 100% Recycled Concrete Aggregate (RCA); 2) 100% Lime Stone (NA); 3) 50% RCA 50% Reclaimed Asphalt Pavement (RAP). Water absorption for each mix has been performed in different size fraction with pyknometer and wire basket methods. The relationship between density, grading and water absorption and its comparison for mixes would be indicating the changes in behaviour of aggregates and future performance of subbase. Laboratory testing showed that 100% Lime Stone had the higher densities than other mixes and water absorption value of 100% RCA was about 40% higher than 50% RCA 50% RAP in 31.5 mm - 4 mm fraction.